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CVE-2021-40830

HighCVSS 8.8 / 10
Published Nov 23, 2021·Last modified Apr 2, 2026
Affected Components(0)

No affected components available

Description

The AWS IoT Device SDK v2 for Java, Python, C++ and Node.js appends a user supplied Certificate Authority (CA) to the root CAs instead of overriding it on Unix systems. TLS handshakes will thus succeed if the peer can be verified either from the user-supplied CA or the system’s default trust-store. Attackers with access to a host’s trust stores or are able to compromise a certificate authority already in the host's trust store (note: the attacker must also be able to spoof DNS in this case) may be able to use this issue to bypass CA pinning. An attacker could then spoof the MQTT broker, and either drop traffic and/or respond with the attacker's data, but they would not be able to forward this data on to the MQTT broker because the attacker would still need the user's private keys to authenticate against the MQTT broker. The 'aws_tls_ctx_options_override_default_trust_store_*' function within the aws-c-io submodule has been updated to override the default trust store. This corrects this issue. This issue affects: Amazon Web Services AWS IoT Device SDK v2 for Java versions prior to 1.5.0 on Linux/Unix. Amazon Web Services AWS IoT Device SDK v2 for Python versions prior to 1.6.1 on Linux/Unix. Amazon Web Services AWS IoT Device SDK v2 for C++ versions prior to 1.12.7 on Linux/Unix. Amazon Web Services AWS IoT Device SDK v2 for Node.js versions prior to 1.5.3 on Linux/Unix. Amazon Web Services AWS-C-IO 0.10.4 on Linux/Unix.

Risk Scores
Base Score
8.8

The vulnerability can be exploited over a local network, such as Wi-Fi. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a high impact on the availability of the system.

Threat Intelligence
8.1

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
0.38%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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